Ti-cr-fe-mn-mo-v alloys



United States Patent Ti-Cr-Fe-Mn-Mo-V ALLOYS John O. Brittain, Bergenfield, N. J., and Paul D. Frost, Groveport, Ohio, assignors, by mesne assignments, to The Battelle Development Corporation, Columbus, Ohio, a corporation of Ohio No Drawing. Application October 4, 1952, Serial No. 313,192

9 Claims. (Cl. 75-175.5)

This invention relates to titanium-base alloys. It has to do, more particularly, with titanium-base alloys containing at least four of the five alloying ingredients chromium, iron, manganese, molybdenum, and vanadium.

Titanium metal is known to possess valuable propertiesrendering it a desirable material for various structuraluses and for other purposes. An outstanding quality of. this metal is its excellent strength-to-weight ratio. It also has good resistance to corrosion and can be used for high-temperature applications. Many applications, however, require considerably greater strength than that possessed by titanium metal, or require a harder material, or both. It is, therefore, an object of this invention to provide alloys of titanium having such desirable properties.

It has been found, as a part of the present invention, that the alloying with titanium of at. least four of the five ingredients chromium, iron, manganese, molybdenum, and vanadium provides high strength, alloys with good ductility. Such alloys also have greatly increased hardnesses over that of unalloyed titanium.

It is, therefore, another object of the present invention to provide high strength, ductile, high hardness alloys containing the ingredients mentioned above.

It is also anobject of thisinvention to provide alloys of titanium having high strengths, good ductilities, and high hardnesses, yet that are useful as materials in products requiring small values of bend radius.

A further object is to provide titanium-base alloys that are age-hardenable.

It is still a further object: of this. inventionto provide alloys of titanium Whose physical properties, including strength and ductility, can be variedover useful ranges by heat treating.

Other objects and advantages of the present invention will be apparent in view of the following description thereof.

In general, this invention relates to alloys of titanium containing at least four of the five alloying ingredients chromium,,iron, manganese,,molybdenum-, and vanadium. In particular, the invention relates to such alloys containing as muchas 4% of each of the foregoing. alloying ingredients. A preferred range has been established in which chromium, iron, molybdenum, and vanadium are present in amounts of about 1% each and manganese is present in amounts of from about 2% to about 4%. A second preferred range has been established in which chromium, manganese, molybdenum, and vanadium are present in amounts of about 1% each and iron is present in amounts of from about 3% to about 4%.

Titanium-base alloys, according to this invention, may be prepared in accordance with present-day melting techniques, which need not be discussed here.

Table I below sets forth measured values of strength,

. "2 hardness, and ductility properties of complex titaniumbase alloys. according.tothepresentinvention. Forcomparison, the;- table alsosetsforth the: measured values of the same properties in unalloyedtitanium. All properties listed are the value as hot-rolled at 1450 F.

TABLE I As hot-rolled properties of complex [Tl-Cr-Fe-Mn-Mo-V alloys] Composition, Percent Ultimate Elonga- M1111- Tensile mum Percent Bend VHN C F .Mn v Strength. in 1 Radius, r I e Mo p. s. 1. mch

1 1 1 l 156, 200 10. 5 Va 337 1' 1 1 1 158, 800 6.0 /16 330 1 1 1- 1 151,600" 10.5 Me 307" 1 1 1 1 151,500 1 1.0 %0 326 1 l 1 l 141, 000 15. 5 V6 304 l 1 1 1" 1 188,300. 2.0 A0 375 1. 1 l 1 2 188,500 7.0 916 361 1' 1 1V 1 3 181,600 6.0 /16 370 1 l 1 1 4 192,500 I 4.0 A 369 l 1 l 2 1 179,600 7.0 l 359. l. 1 1 3 1 198,200 5.9 if: 390 1 1 1 4 1 197, 600 5. 5 V: 370 1 1.. 2. 1 1 179, 900 10.5 %s 363 1 1 3 V 1 1 196, 000 10. 0 M1 397 1 1 4 1 1 217, 500 1 1.75 401 1 2 1 1 1 182,500 7.5 V4 363 1 3 l 1 1 220. 300 3.0 16 442 1 4 1 1 1 211, 900* 5.0 1% 383 2 1 1 1. 1 212,000 3.5 397 3 1 1 i 1 l 203, 200 2. 5 403 4 1 l 1 1 200,000 1 2- 0 $2 401 Unalloyed 74, 200 30. 5 Me. 192

l Broke outside gauge marks. Elongation expressed as uniform elongation between gauge marks on unbroken section.

From Table I above, it is apparent that the alloys containing four of the five listed alloying elements are approximately twice as strong as unalloyed titanium and are muchharder. They are also characterized by good ductility and small values of minimum bend radius. The alloys containing allfive of the listed alloying elements have even greater strengths and hardnesses and are further characterized by good ductilities and low values of minimum bend radius for such high-strength materials. Table I- shows, furthermore, that the complex alloys containingthealloying elements in the preferred ranges set forth above have unusually good values of strength and ductility. Table II below sets forth measured properties of two heat-treated titanium alloys within the preferred ranges of this invention, in. the form of I l-gauge sheet. Each specimen was maintained for one hour at the indicated temperature, in an argon atmosphere, and then either cooled in air to room temperature or quenched in water at a temperature of approximately 32 F., as indicated. Table III below sets. forth measured properties of the same two alloys in the form. of one-half inch roundbar stock. Each specimen was maintained for one hour at the indicated temperature, in an air atmosphere, and then either cooled in air to room temperature, or quenched in water at a temperature of approximately 32 F., as indicated. Table II and Table III show that the physical properties of these alloys, particularly the strength and elongation properties, can be controlled over useful ranges by the selection of appropriate heat-treating conditions to obtain the desired values for these properties within the available range. Such control is important, of course, since, in some applications, it is important to have a high-strength material, while in other applications ductility is of greater importance.

TABLE I1 Properties of heat-treated complex titanium alloys in the form of 14-gauge sheet Mini- Heat Ultimate Composition, Per- Treating Method of Iensile gg fi VHN cent Tgnip Cooling oigueisiglih, in 1 inch Raging,

V l, 300 Water quench 137, 800 18. 5 316 1 Cr, 1 Fe, 3 Mn, 1 1,300 ii 138, 500 19.5 kiz 320 Mo, 1 V 1, 400 Water quench. 161,900 6.0 368 1. 400 Air cool 169, 300 11.0 946 377 1, 300 Water quench. 149, 900 10.0 333 1 Cr, 4 Fe, 1 Mn, 1 1, 300 1r cool 151,900 18.5 %2 338 Mo, 1 V 1, 400 Water quench. 174, 200 1. 5 368 1, 400 Air cool 189.100 6.0 ii 395 TABLE III Properties of heat-treated complex titanium alloys in the form of /2-inch round bar stock T ii n M 1:11 a r i ii E1ng rea g e o o ens e Composition, Percent Temp, C 001mg Strength, gall-egg; VHN

F. p. s. i.

- i288 itiififi $33 33 u (:0 1 Cr, 1 Fe, 3 Mn, 1 Mo, 1 1,40o Water quench. 184. 600 6.0 419 1, 400 Air cool 170, 300 8. 0 388 coo 1 4 Fe, 1 1 M91 1, 400 Water quench. 177, 200 10.0 403 1, 400 Air cool 203, 400 3. 0 424 Tests have shown that the alloys of this invention are of the type referred to as beta stabilized. Their structures consist partly of the body-centered cubic beta phase. These alloys can be age-hardened to provide increased hardness values Where required for particular applications.

It is apparent that new and useful complex alloys of titanium have been described. It will be obvious to those skilled in the art that certain slight changes may be made without departing from the scope of this invention, which is more specifically and particularly defined in the following claims. From the claims, it will be apparent that the scope of this invention is not to be limited by the particular description above, but is to be defined in such broader terms as will come Within the disclosure.

What is claimed is:

1. A titanium-base alloy consisting essentially of from about 1% to about 4% of each of the following alloying elements: chromium, iron, manganese, molybdenum, and vanadium; and the remainder essentially all titanium.

2. A titaniurn-base alloy consisting essentially of about 1% each of chromium, iron, molybdenum, and vana- 1% each of chromium, manganese, molybdenum, and

vanadium; about 4% iron; and the remainder essentially all titanium.

6. A titanium-base alloy consisting essentially of about 1% each of chromium, iron, maganese, and molybdenum; from about 1% to about 4% vanadium; and the remainder essentially all titanium.

7. A titanium-base alloy consisting essentially of about 1% each of chromium, manganese, molybdenum, and vanadium; and the remainder essentially all titanium.

8. A titanium-base alloy consisting essentially of from about 1% to about 4% each of at least four alloying elements selected from the group consisting of chromium, iron, manganese, molybdenum, and vanadium.

9. A titanium-base alloy containing from about 1% to about 4% each of at least four alloying elements selected from the group consisting of chromium, iron, manganese, molybdenum, and vanadium, the remainder essentially all titanium.

References Cited in the file of this patent UNITED STATES PATENTS dium; from about 2% to about 4% manganese; and the remainder essentially all titanium. 2,640,773 Piiler June 2, 195

3. A titanium-base alloy consisting essentially of about 1% each of chromium, manganese, molybdenum, FOREIGN PATENTS and vanadium; from about 3% to about 4% iron; and 718,822 Germany Mar. 24, 1942 the remainder essentially all titanium.

4. A titanium-base alloy consisting essentially of about 1% each of chromium, iron, molybdenum, and vanadium; about 3% manganese; and the remainder essentially all titanium.

i A titanium-base alloy consisting essentially of about 1 OTHER REFERENCES Product Engineering, November 1949, page 147 relied on. r

Journal of Metals, March 1950, pages 498, 499 relied on; pages 488, 494, 497, 502, 503 and 504 also pertinent. 

1. A TITANIUM-BASE ALLOY CONSISTING ESSENTIALLY OF FROM ABOUT 1% TO ABOUT 4% OF EACH OF THE FOLLOWING ALLOYING ELEMENTS: CHRONIUM, IRON, MANGANESE, MOLYBDENUM, AND VANADIUM; AND THE REMAINDER ESSENTIALLY ALL TITANIUM. 